NPC Damage/HP
 

Has anyone already created or know of in existence a spreadsheet showing the different NPCs and their HP Count, Damage Output?

I'm trying to make a decent single player dungeon but I am greatly concerned about the difficulty.

Re: NPC Damage/HP
 

Put every NPC down in an empty map and see for yourself? It doesn't take that long. :p Just HP count and damage output of the individual mobs doesn't tell you much anyways, there's a lot more factors that determine difficulty. You'll likely have to test your map as a whole a few dozen times to get the difficulty right.